1. FIELD OF THE INVENTION
The present invention relates to a container for plate-like objects and more particularly to a container including a container body having an opening formed in a side face thereof for allowing insertion and withdrawal of the objects and a plurality of positioning recesses arranged inside the container body in a direction of the thickness of the object, with an outer periphery of each object being introduced and held in position at each recess, the container further including a hook section provided on an upper face of the container body.
2. DESCRIPTION OF THE RELATED ART
FIG. 24 shows a conventional plate-like object container of the above-described type. As shown, a hook section B provided on an upper face of a container body A includes a single hook member 8 formed like a plate extending in parallel or substantially parallel with the upper face of the container body A and a support table 9 for fixedly supporting the plate-like hook member 8 at a position upwardly spaced from the upper face of the container body (see, e.g. Japanese laid-open patent gazette No. 3-102851).
Referring to a typical application of this type of plate-like object container, when an automatic machine such as an industrial robot is to grid container body A, a robot hand H of the machine will grip the body A as an engaging portion 10 formed e.g. at fingers of the robot hand H comes into engagement with the hook member 8.
However, this conventional art suffers a considerable drawback in case the operation precision of the industrial robot is not very high. In such case, the engagement between the engaging portion 10 of the robot hand H and the hook member 8 may occasionally fail. Also, if the gripping action of the robot hand H becomes excessive, the hand H may damage the hook section B, such that with the application of excessive force to the hook member 8 this hook member 8 or even the entire hook section B may be destroyed at all.
In particular, in this type of plate-like object container, in order to allow the robot hand to grasp each container even when a plurality of containers are placed closely to one another, the hook section B is usually formed small so that in plane view this section B is receded from the outer periphery of the container body A to provide peripheral space for allowing the gripping movement of the robot hand H. In such case, the above-described problem will be more likely to occur. That is, the possibility of damage is even higher in case the hook section B is formed small and fixed at an upwardly distant position from the upper face of the container body via the support table 9.
Incidentally, in order to overcome the problem of the possible damage of the hook member 8 or the entire hook section B, it is conceivable to improve the operation precision of the industrial robot or to provide the robot with a safety device to control the upper limit of the gripping force exerted by the robot hand. However, such measures will be unsatisfactory since the industrial robot thus improved or provided with the additional feature will be necessarily complicated in construction and therefore costly.
Further, such damage may occur also when the container A is displaced from its proper location. In such case, the improvement of the operational precision of the robot alone can not eliminate the possibility of damage.
Therefore, a primary object of the present invention is to provide a plate-like object container which is inexpensive and simple in construction but which can effectively solve the above-described drawback of the conventional device.